I have (had) a Tamron 70-300mm f4 lens and works great for R/C photos or action shots for the money. I paid $200 for it new and it gives you the reach you need for track side shooting. The great all around lens you'll ever need would be the Nikkor 18-200 VR lens but it's a bit pricey.....like all other Nikkor lens. I mainly shot Sigma EX lens now and like them alot......great value and quality.
